The present invention relates to a heater control device and an image forming apparatus including the heater control device. More specifically, the present invention relates to a heater control device using an inverter, and an image forming apparatus including the heater control device.
In a conventional image forming apparatus, an image forming unit forms a toner image. After the toner image is transferred to a medium, a fixing device fixes the toner image to the medium. The fixing device includes a heater for heating. The conventional image forming apparatus further includes a triac for controlling power from a commercial power source, so that the heater is controlled to heat (refer to, for example, Patent Reference).
Patent Reference: Japanese Patent Publication No. 2013-235107
In the conventional image forming apparatus disclosed in Patent Reference, the triac is configured to directly turn on or turn off the commercial power source. Accordingly, it is necessary to dispose different fixing devices according to a voltage of the power source. Further, when it is tried to change power supplied to the heater, it is necessary to control a phase or a frequency number. When it is tried to control the phase, an electrical current may jump rapidly, thereby deteriorating conductive noise. When it is tried to control the frequency number, a flicker may be caused. Among power sources of the conventional image forming apparatus, a direct current (DC) power source is a stabilized power source. However, an alternate current (AC) power source to be applied to the heater is not a stabilized power source.
In order to solve the problems of the conventional image forming apparatus described above, an object of the present invention is to provide a heater control device and an image forming apparatus capable of stably supplying a voltage to a heater regardless of the commercial power source.
Further objects and advantages of the invention will be apparent from the following description of the invention.